Influenza A viruses pose a major public health problem, causing seasonal epidemics and occasional, but devastating global pandemics (Cunha B A (2004) Influenza: historical aspects of epidemics and pandemics, Infectious disease clinics of North America 18(1):141-155), which negatively impacts the global economy.
Birds are natural reservoirs for influenza A viruses, and avian-adapted viruses regularly cross over to humans, either directly (through direct contact) or through an intermediate swine species. Influenza A virus strains rapidly evolve (through antigenic drift) in humans as a consequence of both the complex response of human immune system and rapid geographical movement of human population.
Given the constant evolution of influenza viruses, there is a concern that current avian influenza strains might accumulate mutations that alter their host specificity and allow them to infect humans. The costs of an avian flu pandemic are likely to be significant. In 2005, the threat of such a pandemic resulted in billions of dollars being spent by national governments trying to develop strategies to manage and combat a potential pandemic. Accordingly, improved surveillance techniques and methods of predicting high risk strains of influenza may have value in preventing or minimizing the risk of a human pandemic. There is a well-recognized need for the development of therapeutic agents, specifically including vaccines, for the treatment and/or prevention of influenza infection, particularly of humans. There is also a need for improved surveillance technologies for identifying and/or characterizing emerging strains and there infectivity characteristics.